5G QoS Identifier (5QI) replaces the 4G version of QoS Class Identifier (QCI). Quality of service (QoS) is the lowest level of identification within the 5G system and where policy and charging are enforced. The 5QI is determined by the Access and Mobility Management Function (AMF), Policy Control Function (PCF), and Next Generation Node B (gNB). The AMF then signals to the radio access network (RAN), User Plane Function (UPF), and in turn back to the user equipment (UE) the 5QI values.